Telephonic loud-speaker



Dec. 29, 1931. A. WUNNER I TELEPHONIC LOUDSPEAKER Filed Oct. 26, 1929Patented Dec. 29, 1931 ALOIS wurmnn, or ma age, GERMAVNFI TELEPHONICLouDssrEAKEn.

Application filed October 26, 1929, Serial No.

This invention relates to a telephonic loud speaker of the kind whereinthe vibratory armature of a magnet system is connected by means of aneedle to an acoustic dia- O phragm. Usually the diaphragm is connectedat a single point to the needle. The latter therefore vibrates at rightangles to the diaphragm, and it is necessary to support the latter moreor less rigidly. at the outer edges, an arrangement which leads to adistortion of the sound. The object of the present invention is toproduce an arrangement allowing the diaphragm full freedom of movement,and the invention consists in arranging the diaphragm parallel to theneedle connecting it to the latter throughout the length thereof.

Fig. 1 of the accompanying drawings represents a sectional view of oneform of the improved loud speaker, I

Fig. 2 is a front view of the same,

Fig. 3 is a sectional view of a modified form,

Fig. 4 is a front view of the latter, and

Fig. 5 is a side view of a still further form.

The loud speaker comprises the usual magnet system 1 which receivescurrent through leads 7 and which is provided with an adjusting screw 8.The vibratory armature strip 2 of the-magnet system is supported at bothends and carries, at substantially right angles, a needle 3 which isconnected throughout its length to an accoustic diaphragm 4 so as tohold the latter parallel to its own plane, i. e., substantially at rightangles 'to the armature 2. The diaphragm, which is preferablyrectangular in shape, is formed with a channel 5 for the reception ofthe needle the surface of which is preferably screw threaded orotherwise roughened so as to form engaging points all along the needle.

In the arrangement shown in Figs. 1 and 2, there is only one needle andthis is placed in a central position on the armature 2. The diaphragm isextended beyond the needle, and the projecting portion is coiled so asto form a cylindrical or conical sound magnifier 6. When the armature 2is vibrated underthe influence of the magnetic impulses, the vibrationswill be transmitted to the diaphragm 4 402,753, and in Germany November1, 1928.

principally in the direction of. the arrows A. The diaphragm will alsobeoscillated in the directions about its connecting point with thearmature'2. -The air column within the cylinder orcone 6 will be set incorrespond ing vibrations, and a considerable sound volume, faithfullyreproducing theoriginal sound, will be obtained from the-arrange ment.

The sound-magnifier 6 may be of oval or annular cross-section instead ofround, and it may be provided with -apertures,- reinforce-' merits,coatings or insertions with a view to' modifyingthe sound and regulatingthe 'volume. The diaphragm itself may be treated in asi'milanmannerand-it'may be bent indifferent directions if required. Naturally aperfectly straight andcontinuous diaphragm may also be used.

The entire device may be modified, for instance as shown inFigs. 3 and4, where two or more needles are provided to which the two limbs ofU-shaped diaphragm are connected. p

A further modification is shown in Fig. 5 wherein a U-shaped diaphragmis connected to the needles of two separate magnet systems.

The diaphragm may be made of any suitable material such as paper,cardboard, wood, metal, glass or the like, and the rigidity may bevaried according to requirements. Tension may be applied to thediaphargm in one or more places if necessary. The length of the needlesrelativeto the diaphragm may be varied.

Thedevice, which'can also be used in connection with condensertelephones, is preferably mounted by means of feet on a resonant base. r

I Being of simpler construction than the usual loud speakers, the loudspeaker according to the present inventionwill also be considerablycheaper.

I claim 2- A o 1. A telephonic loudspeaker comprising a magnet systemfitted with avibratory armature, a needle carried'by said armature, andan acoustic diaphragm connected to said needle throughout the length ofthe latter.

2. A telephonic loud speaker comprising a magnet system having aVibratory armature, a needle carried by said armature and maintainedsubstantially at right angles thereto,

5 and an acoustic diaphragm arranged parallel to the needle andconnected thereto throughout the length of the needle.

3. A telephonic loud speaker as claimed in claim 2 wherein the diaphragmis formed 10 with a channel for the reception of the needle.

4. A telephonic loud speaker as claimed in claim 2 wherein the needle isformed with an uneven surface for engagement With the diaphragm.

5. A telephonic loud speaker comprising a magnet system having avibratory armature, a pair of needles carried by said armature andarranged substantially at right angles thereto, and an acousticdiaphragm having channels for the reception of said needles.

6. A telephonic loud speaker as claimed in claim 5 wherein the diaphragmis U-shaped and has its limbs connected to different needles.

7. A telephonic loud speaker comprising a pair of magnet systems havingvibratory armatures, a needle carried by each armature at substantiallyright angles thereto, and a U-shaped acoustic diaphragm having each limbconnected to the needle of a different magnet system and throughout thelength of the needle.

ALOIS WUN N ER.

